AROUND 400 scientists from 80 countries have come together to declare that polio could be wiped off the face of the Earth in five years if plans to eliminate both wild and vaccine-derived polioviruses are implemented. In a ‘Scientific Declaration on Polio Eradication’, eminent scientists and public health experts emphasise the feasibility of eradicating the disease and endorse a recent draft plan that sets out a roadmap to doing so by 2018. The ‘Polio Eradication and Endgame Strategic Plan 2013-2018′ is being developed by the Global Polio Eradication Initiative (GPEI) — an international partnership of the WHO, UNICEF, Rotary International and the US Centers for Disease Control and Prevention. The latest version of the draft plan was published earlier this month. “There has been a perception that polio is not eradicable. We developed the declaration to underscore the science behind [this goal] and to say that this is doable,” says Zulfiqar Bhutta, head of the Division of Women and Child Health at the Aga Khan University in Pakistan. He is the joint leader of the declaration, along with Walter Orenstein, associate professor at the Emory Vaccine Center in the United States. “The declaration also calls for additional resources to eliminate the gap in funding needed for the eradication plan,” Bhutta says. He adds that improved vaccination strategies are needed to address the polio endgame. One of the declaration’s signatories, David Heymann, chair of Public Health England’s advisory board in the United Kingdom, says that much remains to be done. “GPEI has set a target of 2018 and it has been encouraged by the fact that India has now become polio-free, which was a challenge. The remaining three countries that are endemic — Nigeria, Afghanistan and Pakistan — have challenges of their own. The main challenge is to vaccinate all the children in order to establish immunity in the communities,” Heymann says. There were only fewer than 250 polio cases reported from five countries last year, compared with 350,000 from 125 countries in 1988. “The vaccine seems to have worked in most countries, so there’s no reason it wouldn’t work in the countries that are left,” he explains, adding that “the technology that we need to eradicate polio is there”. The GPEI plan aims to strengthen routine immunisation programmes and the surveillance of virus transmission. The declaration supports the plan’s objective to stop using the trivalent oral polio vaccine that contains all three types of wild polioviruses — types 1, 2 and 3 — in an attenuated, albeit living, state. The continued use of wild poliovirus type 2, which was eradicated in 1999, in this vaccine has been found to be a major cause of vaccine-derived polio outbreaks. To avoid further such outbreaks, new inactivated polio vaccines (IPV), which are given intravenously, will be introduced to the routine immunisation programmes in countries that rely on oral vaccines, according to the plan. Recently developed bivalent oral vaccines, lacking the type 2 poliovirus, will then replace the trivalent vaccines. The declaration acknowledges these steps as “strong solutions to challenges”. Sona Bari, a spokeswoman for the GPEI in Geneva, Switzerland, says the scientists’ declaration is a strong endorsement of her organisation’s plan. “Polio eradication is a global win, so we need every single country to fund and finance it as well,” she says. John L. Sever, vice- chair of the International PolioPlus Committee of Rotary International, says: “The scientific declaration is consistent with the objectives of the strategic plan and its importance. Scientific support and advice have been vital to the development of the strategic plan and [will be] in its implementation.” (SciDev)
Agrochemicals blamed for kidney disease
A TEAM of Sri Lankan and WHO scientists has linked the high prevalence of chronic kidney disease of uncertain aetiology (CKDu) on the island to indiscriminate use of agrochemicals including fertilisers and pesticides. In its final report released on February 28, the team, led by WHO researcher Shanthi Mendis, identified districts in the north, centre and east of the island and the rice-growing areas as “most vulnerable”. While uncertainty prevailed over the exact cause of CKDu, the number of affected people in the country had grown to 450,000, according to estimates by the health ministry, which commissioned the WHO study. WHO representative in Sri Lanka, Firdosi Rastam Mehta, said that a new form of chronic kidney disease unlinked to diabetes mellitus, hypertension, kidney damage or other known causes, has emerged in the identified areas. The new disease has been characterised as “slowly progressive, probably starting in the second decade of life, and asymptomatic (without apparent symptoms) until very advanced,” said health secretary Nihal Jayatillake. These residues, according to government epidemiologist Paba Palihawardene, are demonstrative of the extent of the environmental distribution of pesticides, which may be contributing to the prevalence of the disease. Cadmium, lead and arsenic values in phosphate fertilisers from the endemic areas are higher than the levels reported in agricultural soils in many other countries, according to the study. It detected pesticide residues in urine, hair and nail samples taken from people in the worst-affected North Central Province. “There is strong evidence available of chronic exposure to low levels of arsenic, and in susceptible individuals, co-exposure to low levels of cadmium and arsenic giving rise to more pronounced renal (kidney) damage than exposure to each element alone,” Priyani Paranagama, head of the chemistry department, Kelaniya University, said. CKDu involves kidney damage and loss of the organ’s function of excreting waste products over three or more months. The absence of clinical symptoms until late stages makes diagnosis and treatment difficult. The WHO study called for a robust regulatory framework “to improve the quality control of imported fertilisers, particularly with regard to nephro-toxic (harmful to kidneys) agents such as cadmium and arsenic.” Oliver Illeperuma, head of the chemistry department, Peradeniya University, said that more research was needed. “There are multiple causes identified through different research attempts, but we do not have sound knowledge on this growing health crisis,” he said. (SciDev)
——————————————————————-